RU2599093C2 - Fuel injection device, internal combustion engine and method of controlling fuel injection device based on gasoline and based on compressed natural gas - Google Patents

Abstract

FIELD: engines.

SUBSTANCE: invention can be used in fuel feed systems of internal combustion engines (ICE). Injection apparatus (1′) for an internal combustion engine (1), having first injection arrangement (3) for injecting fuel (4) of a first, natural gas-based fuel composition and second injection arrangement (5) for injecting fuel (6) of a second, gasoline-based fuel composition. First injection arrangement (3) has first injection valve (7) for injecting fuel (4) of first fuel composition both in direction of first inlet opening (10) of combustion chamber (2) of internal combustion engine and in direction of second inlet opening (20) of combustion chamber (2). Second injection arrangement (5) has second injection valve (12) for injecting fuel (6) of second fuel composition in direction of first inlet opening (10) and separate, third injection valve (22) for injecting fuel (6) of second fuel composition in direction of second inlet opening (20).

EFFECT: technical result is increased efficiency of operation of a system for injecting two types of fuel on different operating modes of internal combustion engine.

8 cl, 3 dwg

Description

State of the art

The present invention relates to a fuel injection device according to the preamble of claim 1.

Such fuel injection devices for internal combustion engines (ICE) are well known. So, for example, from DE 102008043930 A1, a fuel injection system for internal combustion engines is known, which is designed for the use of fuels of two or more different types and which has fuel injectors that are optionally connected to different containers containing different fuels. In such a fuel injection system, it is primarily intended to use the same fuel injectors both for injecting gasoline and for supplying a gas such as compressed natural gas and liquefied (hydrocarbon) gas. The disadvantage of such a fuel injection system is that when injecting fuels based on gasoline, they need to be supplied at a different rate than when supplying fuels based on gas. However, the limits within which the amount of fuel dosed by any fuel injector can be varied, i.e. those limits in which fuel injection with a fuel nozzle is possible with a certain accuracy of its dispensing are limited.

Summary of the invention

An advantage of the fuel injection device of the invention, the internal combustion engine of the invention and the method of controlling the fuel injection device of the invention, as claimed in the respective independent claims, over the prior art solutions consists, on the one hand, in reducing exhaust emissions (OG), and on the other hand, in increasing the power developed by the internal combustion engine. This is achieved because the fuel of the first composition, the main component of which is mainly natural gas, is injected exclusively by the first injection unit, while the fuel of the second composition, the main component of which is mainly gasoline, is injected exclusively by the second injection unit with two separate fuel injectors. When creating the invention, it was found that the operation of ICE with a low exhaust gas emission is achieved when the ICE operates on fuel of the second composition during the start-up and warm-up periods and in the low load range, and on the fuel of the first composition in the increased, respectively full load range. When operating an internal combustion engine using natural gas fuel, it must be supplied with a corresponding fuel nozzle in a significantly larger amount than when operating an internal combustion engine using gasoline-based fuel, and therefore relatively high demands are placed on the range of fuel flow control through its injection device. Separation of fuel injectors into those that are used to inject only natural gas-based fuels and those that are used to inject only gas-based fuels makes it easy to ensure that the high requirements for the available range of fuel flow control through the appropriate fuel injector. Gasoline-based fuel injection is required primarily during the start-up and warm-up period of ICEs, since the injection of natural gas-based fuel is relatively ineffective for starting ICE. Therefore, the second injection unit is used precisely during the start-up and warm-up period of the internal combustion engine, and when it is operating in full load mode, it is primarily throttled or completely turned off. The use of two separate - the second and third - fuel nozzles contributes to a uniform and stable combustion of fuel precisely during the start-up and warm-up period of the internal combustion engine, since each fuel nozzle only needs to inject fuel of the second composition with a lower consumption, thereby achieving a lower density of droplets in the sprayed fuel stream , i.e. the characteristic size of droplets of atomized fuel is effectively reduced, primarily their Sauter diameter, as a result of which the combustion of the air-fuel mixture in the combustion chamber is faster and more stable. Another advantage is that the fuel injection device has two fuel injection points located separately from each other, which is achieved due to which the degree of freedom provides the possibility of optimal fuel injection with minimal condensation on the walls. As a result, flaws in the combustion process, misfires or incomplete combustion of the air-fuel mixture are prevented and the formation of primary exhaust gas is reduced. This factor is primarily during the start-up and warm-up of the internal combustion engine, i.e. when it is cold, which does not yet ensure (complete) conversion of harmful substances into a harmless catalytic converter, it leads to a decrease in the emission of harmful substances from exhaust gas at the outlet of the catalytic converter. In addition, better combustion of the air-fuel mixture in the combustion chamber leads to a change in the ignition timing to a later one with the same smoothness of the engine, which further leads to an increase in temperature in the combustion chamber, and thereby to the formation of hotter primary exhaust gases. Due to this, during the start-up and warm-up of the internal combustion engine, the catalytic converter heats up faster and reaches its initial operating temperature faster, starting with which the catalytic converter works efficiently. Thus, due to the use of two separate fuel injectors, a significantly smaller number of primary exhaust gases is formed as a whole during the start-up and heating of the internal combustion engine. The advantage associated with a reduction in the amount of primary exhaust gas generated is the possibility of reducing the size of the catalytic converter and saving the precious metals necessary for it. The best combustion of the air-fuel mixture and the resulting increase in the smoothness of the internal combustion engine allow, in addition, to reduce the rotational speed of the internal combustion engine shaft at idle, which, in turn, also leads to a reduction in exhaust emissions when the internal combustion engine runs on fuel of the second composition. In high load mode, the second injection unit is throttled and / or turned off, and fuel based on natural gas is supplied to the internal combustion engine, thereby achieving a relatively high power with low exhaust emissions and low fuel consumption. Due to the lower content of impurities in natural gas, its combustion as a whole is more complete as compared to gasoline and is thereby accompanied by the formation of a smaller amount of exhaust gas. As a result, when the internal combustion engine operates under load and full load conditions, a significant reduction in the amount of exhaust gas is achieved. The internal combustion engine proposed in the invention is preferably an internal combustion engine with forced ignition of the working mixture and with distributed injection of fuel into the intake channels (or injection of fuel into the intake manifold) for a trackless vehicle, mainly for a car. Such an internal combustion engine preferably has more than one cylinder.

Various preferred embodiments of the invention are given in the dependent claims, as well as discussed in the following description with reference to the accompanying drawings.

In one of these preferred embodiments, the second and third fuel nozzles are located in the inlet pipe leading to the combustion chamber, preferably on the lower wall portion of the inlet pipe facing the combustion chamber. The advantage associated with a similar arrangement of the second and third fuel nozzles is that their arrangement from the point of view of aerohydrodynamics is more favorable with respect to the return flow of exhaust gases leaving the combustion chamber, thereby reducing the risk of clogging of the second and third fuel nozzles.

In another preferred embodiment, the first fuel nozzle is located in the inlet pipe, preferably on the upper wall portion of the inlet pipe facing away from the combustion chamber. The advantage associated with the similar arrangement of the first fuel nozzle is therefore the possibility of making the fuel injection device particularly compact in terms of the installation space occupied by it, since the first fuel nozzle is located on the wall of the inlet pipe which is opposite to the second and third fuel nozzles.

In another preferred embodiment, the inlet pipe is divided in the area between the second injection unit and the combustion chamber of the internal partition into a first inlet channel leading to the first inlet and a second inlet channel leading to the second inlet, the second fuel nozzle being located in the region of the first inlet channel and the third fuel injector in the area of the second inlet channel. In a preferred embodiment, the second and third fuel nozzles are further located separately from each other and, above all, are also configured to be controlled separately from each other. A variant is also possible in which only one of both of these fuel injectors is controlled, respectively.

In another preferred embodiment, the distance between the second fuel nozzle and the first inlet and the distance between the third fuel nozzle and the second inlet is less than the distance between the first fuel nozzle and the first or second inlet. The distance between the second injection unit and the combustion chamber is preferably chosen small in order to reduce the time spent by the sprayed fuel of the second composition on the passage to the inlet. In accordance with this, the evaporation of fuel based on gasoline occurs in the combustion chamber, which is thereby cooled. As a result, the detonation resistance is increased, due to which the internal combustion engine, first of all, when it is operating in full load mode, becomes capable of developing greater power. Therefore, this option is suitable for creating a particularly powerful internal combustion engine.

In an alternative preferred embodiment, the distance between the second fuel nozzle and the first inlet and the distance between the third fuel nozzle and the second inlet is greater than the distance between the first fuel nozzle and the first or second inlet. Accordingly, the distance between the second injection unit and the combustion chamber is relatively large, and therefore, the time taken by the sprayed fuel of the second composition to travel the path to the inlet increases. A related advantage is that the efficient evaporation of fuel droplets begins already in the intake pipe and that this results in a relatively stable and high-temperature combustion of the air-fuel mixture in the combustion chamber. As a result of this, first of all, during the start-up and warm-up period of the internal combustion engine, the flammability of the air-fuel mixture is improved, and the heating of the catalytic converter is also accelerated. At the same time, exhaust emissions are reduced. Therefore, this option is suitable for creating a particularly low-toxic internal combustion engine.

In another preferred embodiment, the second and third fuel nozzles have only one spray hole for injecting fuel of the second composition and / or are designed for fuel injection at a lower consumption rate than at least one first fuel nozzle. A related advantage is therefore that it is possible to optimize the limits within which the metered amount of fuel of each of both different compositions can be varied. The first fuel nozzle alternatively has either a single first spray opening or at least two separate first spray holes for injecting natural gas based fuel in the direction of the first and second inlets. Obviously, an alternative to this is also possible variant with the implementation of the first injection unit with two or more first fuel nozzles, each of which primarily has only one first spray hole and which are located in the inlet pipe or in the first and second inlet channels.

In another preferred embodiment, the second and third fuel injectors are made with different design parameters, and each of them is designed to inject fuel of the second composition in an amount different from the amount of fuel injected by the other of them. This approach allows you to significantly expand the limits within which you can vary the dosed amount of fuel, for example, by controlling only the fuel nozzle, which in its design parameters is designed for lower fuel consumption.

Another object of the present invention is an internal combustion engine with a fuel injection device of the invention.

Another object of the present invention is a method for controlling the operation of the fuel injection device of the invention, in which the first fuel nozzle of the first natural gas composition is injected simultaneously in the direction of the first inlet and in the direction of the second inlet, the second fuel nozzle in the second gasoline-based composition is injected mainly only in the direction of the first inlet, and the fuel of the third fuel injector cerned composition is injected substantially only in the direction of the second air inlet. Accordingly, the above advantages are achieved in terms of reducing exhaust emissions, as well as increasing power. In this way, it is possible to expand to the maximum possible extent the limits within which the metered amount of fuel can be varied in order to ensure its injection in exact, actually required quantities.

In one embodiment, at least one of the first fuel injectors injects exclusively fuel of the first composition, and each of the second and third fuel injectors injects exclusively fuel of the second composition.

In another preferred embodiment, during the start-up and warm-up period of the internal combustion engine, fuel of the second composition with the second and third fuel nozzles is mainly injected, and during the operation of the internal combustion engine in the load mode, fuel of the first composition is primarily injected with the first fuel nozzle. This ensures the most efficient use of fuels of a different composition in accordance with specific requirements.

Below the present invention is described in more detail by the example of some variants of its implementation with reference to the accompanying drawings.

Brief Description of the Drawings

In FIG. 1 is a schematic plan view showing an internal combustion engine with a fuel injection device according to a first embodiment of the present invention.

In FIG. 2 is a schematic sectional view showing an internal combustion engine with a fuel injection device according to a second embodiment of the present invention.

In FIG. 3 is a schematic plan view of a fuel injection device according to a second embodiment of the present invention.

Description of Embodiments

In various drawings, the same parts and elements are always provided with the same reference numbers and, therefore, are also usually indicated in each case, respectively, mentioned only once.

In FIG. 1 schematically in plan view shows an internal combustion engine 1 with a fuel injection device 1 ′ according to a first embodiment of the present invention, wherein such an internal combustion engine has a cylinder with a combustion chamber 2 and a piston 2 ′ moving therein. The wall of the combustion chamber 2 has a first and second inlet openings 10, 20, through each of which a fuel-air (working) mixture enters the combustion chamber 2, and first and second exhaust openings 30, 31, through each of which from the combustion chamber 2 to the first and the second exhaust channels 32, 33, respectively, are displaced by the primary exhaust gas, initially formed as a result of combustion of the air-fuel mixture. ICE 1 has a first inlet valve 10 ′, designed to block the first inlet 10 and located between the first inlet channel 11 and the combustion chamber 2. The engine 1 further has a second inlet valve 20 ′, designed to close the second inlet 20 and located between the second inlet channel 21 and the combustion chamber 2. The first and second inlet channels 11, 21 from the side facing away from the combustion chamber 2 depart from the common inlet pipe 9, through which fresh air enters in a metered amount through a throttle valve (not shown) in the direction of the combustion chamber 2. The first and second inlet channels 11, 21 are mainly separated from each other by a partition 42 located in the inlet pipe 9. The fuel injection device 1 ′ has first and second injection units 3, 5 designed to inject fuel 4, 6 in the direction of the first and second inlets the openings 10, 20, respectively, into the first and second inlet channels 11, 21. The first injection unit 3 has a first fuel nozzle 7 with at least one spray opening 8 through which fuel 4 of the first composition is simultaneously injected in the direction enii first and towards said second inlet openings 10, 20. Fuel first composition consists essentially of natural gas, which, when the internal combustion engine 1 during load (full) provides a relatively complete combustion of the mixture, i.e., its combustion with low exhaust emissions and with the return of high power. Since the use of natural gas-based fuel during the start-up and warm-up period of the internal combustion engine is relatively inefficient, the fuel injection device G also has a second injection unit 5 for injecting fuel 6 of a second composition. The fuel of the second composition consists primarily of ordinary gasoline. The second injection unit 5 has a second and separate third fuel nozzle 12, 22. The second fuel nozzle 12 has a single spray hole 14 through which fuel 6 of the second composition is injected mainly only in the direction of the first inlet 10. Similarly, the third fuel nozzle 22 has a single third spray hole 24 through which fuel 6 of the second composition is injected mainly only in the direction of the second inlet 20. The first, second and third fuel nozzles 7, 12, 22 are made controlled separately from one another. In this embodiment, the distance between the second fuel nozzle 12 and the first inlet 10, as well as the distance between the third fuel nozzle 22 and the second inlet 20 is less than the distance between the first fuel nozzle 7 and the first or second inlet 10, 20. The second and third fuel nozzles 12, 22 in their design parameters are designed to inject fuel with a lower fuel consumption than at least one first fuel injector 7, since fuel 4 based on natural gas needs to be injected into a large x amounts compared with the fuel injection 6 based on gasoline. Therefore, the first fuel nozzle 7 serves solely to inject fuel 4 of the first composition, while each of the second and third fuel nozzles 12, 22 is injected exclusively with fuel 6 of the second composition. The injection of fuel 6 of the second composition occurs mainly during the start-up and heating of the engine 1.

The injection of fuel 4 of the first composition occurs mainly during the operation of the internal combustion engine in the load and full load conditions. The control of the first, second and third fuel nozzles 7, 12, 22 is preferably carried out by a suitable control system depending on the respective operating parameters, whereby the ratio between the injected amount of fuel 4 of the first composition and the injected amount of fuel 6 of the second composition is regulated depending on actual needs, and above all in a continuous mode, with the goal of minimizing exhaust emissions while developing sufficient capacity. ICE 1 preferably has several similar cylinders. In addition, the internal combustion engine 1 in the preferred embodiment, is an internal combustion engine with forced ignition of the working mixture for a car.

In FIG. 2 is a schematic cross-sectional view illustrating an ICE 1 with a fuel injection device 1 ′ according to a second embodiment of the present invention. The second embodiment is basically the same as the first embodiment shown in FIG. 1, while the second and third fuel nozzles 12, 22 are located in the area facing the combustion chamber 2 of the lower portion 40 of the wall of the intake pipe 9. The first fuel nozzle 7 is located in the area facing the combustion chamber 2 of the upper portion 41 of the wall of the intake pipe 9.

In FIG. 3 schematically in plan view shown in FIG. 2, a fuel injection device 1 ′ according to a second embodiment of the present invention.

Claims (8)

1. A fuel injection device (1 ′) for an internal combustion engine (1) having a first fuel injection unit (3) of a first composition based on natural gas and a second fuel injection unit (5) of a second composition (6) based on gasoline, while the first injection unit (3) has a first fuel injector (7) for injecting fuel (4) of the first composition simultaneously in the direction of the first inlet (10) of the combustion chamber (2) in the internal combustion engine (1) and in the direction of the second the inlet (20) of this combustion chamber (2) and the second block (5) is injected Oia has a second fuel nozzle (12) for injecting fuel (6) of the second composition mainly only in the direction of the first inlet (10) and a separate third fuel nozzle (22) for injecting fuel (6) of the second composition mainly only in the direction of the second inlet openings (20), characterized in that the second and third fuel nozzles (12, 22) are located in the inlet pipe (9) leading to the combustion chamber (2) on the lower portion (40) of the wall of this inlet pipe facing the combustion chamber (2) (9), and the first fuel injector (7) is located in an inlet pipe (9) on the end facing away from the chamber (2) combustion upper portion (41) of the wall of the intake pipe (9). 2. A fuel injection device (1 ′) according to claim 1, characterized in that the inlet pipe (9) is divided in a section between the second injection unit (5) and the combustion chamber (2) of the internal partition (42) onto a lead to the first inlet (10) the first inlet channel (11) and the second inlet channel (21) leading to the second inlet hole (20), the second fuel nozzle (12) being located in the region of the first inlet channel (11) and the third fuel nozzle (22) ) - in the area of the second inlet channel (21). 3. A fuel injection device (1 ′) according to claim 1, characterized in that the distance between the second fuel nozzle (12) and the first inlet (10) and the distance between the third fuel nozzle (22) and the second inlet (20) are less the distance between the first fuel nozzle (7) and the first or second inlet (10, 20). 4. A fuel injection device (1 ′) according to one of the preceding paragraphs, characterized in that the second and third fuel nozzles (12, 22) have only one spray hole (14, 24) for fuel injection (6) of the second composition and / or in their design parameters are designed to inject fuel with a lower fuel consumption than at least one first fuel injector (7). 5. An internal combustion engine (1) with a fuel injection device (1 ′) according to one of the preceding paragraphs. 6. The method of controlling the operation of the device (1 ′) fuel injection according to one of paragraphs. 1-4, consisting in the fact that the first fuel nozzle (7) fuel (4) of the first composition based on natural gas is injected simultaneously in the direction of the first inlet (10) and in the direction of the second inlet (20), the second fuel nozzle (12 ) fuel (6) of the second gasoline-based composition is injected mainly only in the direction of the first inlet (10), and with the third fuel nozzle (22) fuel (6) of the second composition is injected mainly only in the direction of the second inlet (20). 7. The method according to p. 6, characterized in that at least one first fuel nozzle (7) injects exclusively fuel (4) of the first composition, and each of the second and third fuel nozzles (12, 22) injects exclusively fuel (6 ) of the second composition. 8. The method according to p. 6 or 7, characterized in that during the start-up and warm-up period of the internal combustion engine (1), mainly inject fuel (6) of the second composition of the second and third fuel nozzles (12, 22), and during engine operation ( 1) internal combustion in the load mode inject mainly fuel (4) of the first composition of the first fuel nozzle (7).

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